Patent GB-1356011-A (GB)
Title: Method and conveyor arrangement for feeding goods in a closed feed path
IPC: A24C5/352
Filed: 1971-06-04
Abstract: 1356011 Controlling feeding and discharge of endless conveyers HAUNI-WERKE KORBER & CO KG 4 June 1971 [20 June 1970] 19107/71 Heading B8A [Also in Division G4] Goods are fed in a closed feed path from intake stations at which the goods are supplied automatically to the feed path, to removal stations at which the goods are automatically removed from the feed path, the occupation condition of the feed path being monitored and control signals being supplied in such a manner that a desired occupation condition is maintained by inserting goods in conveying sections with relatively low concentration of goods and removing goods from conveying sections with relatively high concentration of goods. The feed path consists of a continuously-moving chain supported by rollers on U-shaped tracks, hooks hanging from the chain. The intake stations are in one half of the path and can each transfer empty magazines (containers) from a hook and transfer magazines filled with cigarettes to a hook, each intake station having associated with it a cigarette making machine, a filter adding machine and a magazine filler. The removal stations are in the other half of the path and can each transfer full magazines from a hook and transfer empty magazines to a hook, each removal station having associated with it a filler supplying a packing machine. The transfers are controlled by a computer arrangement in response to demand (ready for transfer) signals from lifting units (one per station), the lifting units also supplying (to the computer) signals indicating completion of transfer. Carried with each hook are axially-displaceable control discs, and a lever which is pulled down against a spring when the hook holds a magazine carrier (the latter holding three magazines either full or empty, magazines being transferred to or from a hook in such a carrier). The positions of the lever and discs are sensed by switches to provide control signals from the lifting units (which are used during the transfers). As the hooks circulate round the feed path, the contents of a loop of data registers, provided in connection with the removal stations, circulate around the loop, a register being provided for each hook and having storage positions for the status of the hook (empty, or carrying empty magazines, or carrying full magazines), the number of the hook, the number (address) of the register contents, and the numbers of two lifting units. Demand signals from lifting units at the removal stations are stored in stores respective to the stations, which stores are interrogated periodically. Detection of a demand signal causes interrogation in turn of the registers in each of a series of overlapping interrogation ranges (zones) in turn (each interrogation range being a series of consecutive registers upstream), starting at the register corresponding to the lifting unit supplying the demand. For each range in turn counts are made of the number of hooks in each of the three statuses respectively, the difference between the count of empty hooks and that of empty magazine hooks and the difference between the count of empty hooks and that of full magazine hooks being calculated and stored. Two comparators determine for which range the first difference is largest and for which the second difference is largest, these being the most favourable regions for supplying empty magazines and removing full magazines. Suitable hooks are then determined in these regions by interrogating the register loop for hook status, and may involve comparison (to determine which is greater) of a number of a lifting unit from one of the registers with the number of the lifting unit providing the demand. On determination of a suitable hook, the number of the lifting unit providing the demand and its occupation status are entered into the appropriate register. A transfer signal is sent to the lifting unit when the register contents including the number of this unit reaches the corresponding position in the register loop. The signal indicating completion of transfer causes updating of the register contents. Similar control arrangements are provided for the intake stations, except that here the differences of counts formed are between those for empty hooks and those for full magazine hooks and between those for empty magazine hooks and those for empty hooks. Modifications: (a) the interrogation ranges for the two types of transfer for either set of stations can be different, (b) hook status may also include cigarette brand in the case of full magazine hooks, (c) the circulating loop of registers may be replaced by a cyclicallyaddressed set of registers each permanently associated with a particular hook, (d) a magazine carrier may always be placed on a hook from which one has just been removed so there are no empty hooks, (e) stored hook status and actual hook status may be kept in agreement by a sensor interrogating all the hooks, any discrepancy between its output and the stored status causing correction of the latter and optionally an alarm. An output from the computer may supply records of the supply and removal of magazines and the distribution of hook statuses over the feed path, and a computer input may be used to enter programme changes.